In fact, Zhang Chen could produce brain tissue on his own using his Flesh and Blood Ability.
However, according to the third chapter, "Devour Brain," the process of breaking down and reconstructing telencephalic tissue was extremely troublesome. Evil Mouth Elder alone could not possibly handle it, because every piece of separated telencephalic neural tissue needed to absorb Zhang Chen's understanding of the third chapter.
Moreover, Zhang Chen had to determine the optimal arrangement for every piece of brain tissue separated throughout his body. After all, turning brain tissue into part of the body completely defied the structure of the human body and overturned common sense. Zhang Chen was using book knowledge to experiment on his own body for the first time.
"Evil Mouth Elder, slow White Navel's digestion to its lowest possible speed. I'm not yet confident that I can completely integrate the brain tissue with the Ghoul body. Slow it down for now. Once I gradually succeed with the earlier parts, we can slowly increase the speed later."
"Boy, are you planning to use this time imprisoned in the Wood Realm to master this book that surpasses even my understanding?" Evil Mouth Elder had already fully controlled White Navel's movement within the digestive pool as he asked Zhang Chen.
"Yes. With my current abilities, I can't break free from the restraints of a Great Realm. As for matters outside, Senior Green Ghost, Jia Xin, and Jin Geng are handling them. If even they are defeated by Yu Ming, then I can do nothing in my current state. The only possibility is to fully comprehend the upper volume of the Body Devouring Heart Sutra left behind by Senior Devour Hunt and reform my body in every aspect."
"Evil Mouth Elder, you said that comprehending the upper volume would allow one